Sight for blast-furnaces.



T. M; CUNNINGHAM. SIGHT FOR BLAST FURNACES.

10N FILED MA 22,1911.

Patented Nov. 28, 1911.y

THOMAS lVI. CUNNINGHAM, 0F READING, PENNSYLVANIA.

SIGHT FOR BLAST-FURNACES.

Specification of Letters Patent.

Application filed May 22, 1911.

Patented Nov. 28, 1911. Serial No. 628,883.

To all whom it mag/concern:

Be it known that I, THOMAS M. CUNNING- HAM, citizen of the UnitedStates, residing at Reading, in the county of Berks and State ofPennsylvania, have invented certain new and useful Improvements inSights for Blast-Furnaces, of which the following is a specification.

This invention relates to improvements in sights for blast furnaces, andthe object is to provide a device for attachment t0 the furnace twyer,whereby a view of the inside of the furnace may be had, and one in whichthe blast of air may be shut off when desired, as for instance when itis desired to change the glass, or to clean the opening into the twyer.

The invention consists of placing a valve in the casing comprising thesight, whereby the direct passage from the point of vision to thefurnace may be closed.

Another object is to provide means for blowing out any obstruction thatmight collect in the casing, between the valve and,

the furnace.

The invention is more fully described in the following specification andclearly illustrated in the accompanying drawing, in which Figure l is acentral longitudinal sectional view of my device, applied to the twyer.Fig. 2 is a sectional view on line 2-2 of Fig. l. Fig. 3 is a View online 3 3 of Fig. 1.

The numeral l designates the twyer, into which my device is secured bymeans of a threaded end, 2.

3 designates the casing of the device, which is formed with alongitudinal central opening t extending entirely through it, and theforward end of the casing is reduced in diameter and screw-threadedexternally. On this end of the casing, I secure a sight cap 5, which isprovided with a central opening 6, smaller than the opening in thelcasing 2, and in line therewith. In this cap, I locate a plate of glass7, so arranged that it rests against the end of the casing, but betweenwhich and the glass I interpose a resilient body 8, preferably of sheetasbestos.

The casing is provided with a. plug valve 9, which valve is adapted toturn in the casing by means of an operating handle 10. The valve` isformed with a transverse opening passing through the body thereof, and

adapted to lie in the path of, and register with the central opening inthe casing, when the parts are in normal position, as shown in Fig. l.When however, it is desired to remove the cap 5 for the purpose ofcleaning or replacing the glass 7, the handle of the valve is turned tothe position indicated by dotted line p1, which will place the openingin the valve at right angles to the opening in the casing, andeifectually shut off the blast from the outlet. When however Vit isdesired to cleanV out the passage in the casing, between the valve andthe furnace, the'handle of the valve is turned to the position indicatedby dotted line p2, which will bring the opening in the casing inregister with a right angled side outlet 1l, in the valve, whichcommunicates with the transverse opening therein.

It will therefore be seen that with my device, the sight may be repairedat any time without interfering with the furnace blast, as it will beonly necessary to close the sight opening or passageway by turning thevalve; also, when it is desired to clean out the device, the blast ofthe furnace may be utilized, by turning the valve in the oppositedirect-ion, which will open the passage to the side outlet 11 in thecasing.

Having thus described the invention, what I claim and desire to secureby Letters Patent is In a sight for blast furnace twyers, thecombination of a casing provided with means for attaching it to thetwyer and having a central longitudinal opening therethrough, theforward end of the casing being reduced in diameter and screw-threadedexternally; said casing having a side outlet communicating with thelongitudinal opening; aplug valve located in the casing and providedwith a transverse opening through its body and a side outlet from saidopening; a cap adapted to screw onto the end of the casing; a glassinterposed between the cap and the end of the casing; a resilient bodyon both sides of the glass; said cap having a central opening in linewith the central opening in the casing.

In testimony whereof I affix my signature in presence of two witnesses.

TI-IOS. M. CUNNINGHAM. Witnesses:

CLARA E. YOUNG, ED. A. vKELLY.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. G.

